The present invention relates generally to agricultural machinery and, more particularly, to improvements to balers for harvested crops.
Round balers are known in various designs. For example in German Patent 3 327 042 C2 is described a large baling press with several driven press rollers and a device for receiving a web roll of wrapping material for a pressed bale. To maintain uniform tension of the wrapping material, a brake rod is mounted between two pivot levers acting on the web roll. The brake rod also reduces the weight of the roll and hence reduces the friction in the net recess. Both effects ensure that the net tension decreases as the size of the roll decreases. The pivot levers are mounted on a shaft which is connected by stays to the side walls of the press. The contact pressure of the brake rod on the web roll is obtained by a tension spring acting on a lever system and arranged between the pivot levers and the press frame. The design has the disadvantage that, as the outside diameter of the web roll decreases and the angle of inclination of the pivot levers decreases as a result, the effective length of the tension spring decreases as well. Accordingly there is also a resultant decrease in the spring force.
It is the object of the invention to provide a braking device for a web roll of bale wrapping material that ensures functionally sufficient web tension for the process of wrapping the pressed bales over the whole diameter range of the outer periphery of the web roll.